Rose blinked a few times but remained silent. What he said made complete sense. The Doctor that was laying down next to her wasn't the same Doctor that fancied bowties and fezzes. Thinking of the Doctor as different people with each regeneration was both easy and hard for Rose to do. There were of course significant differences, and yet some were still the same.
"I know. I guess it stems from what you told me after you regenerated. Everything about you was completely different and you had to convince me you were still the same person." Rose chose her tone carefully so she wouldn't come across as being too upset or feel like she was accusing the Doctor of something. "You cared about me before you changed and you carried those feelings, growing a bit more too. I know I'm being silly. Sometimes it's hard going back and forth between the two of you being different and still being the same person."
Hoping that he would feel any guilt, she smiled and placed her hand on his cheek. "Don't feel like you've done something wrong. And I hope you know that the life I have here with you is utterly amazing. One that I could never give up, not for anything or anyone."